I believe Texas drivers license for large motorhomes may be one of the most confusing subjects. When we upgraded to a larger MH, the Texas salesperson (who seemed to be knowledgeable) told us no special license was needed.
We then asked our insurance agent (who owns a large MH) and he said nothing special was needed. He said it was called a "house car," a term we had never heard before.
We then called the DPS office and they said we needed a Class B, non CDL.
When we took delivery of our MH, we told the salesperson what the DPS had said. He then made his own phone calls, to whom I do not remember, and assured me we do not need a Class B license.
We proceeded to study for the test, but when we went to the DPS office, we asked for an explanation of one line about an exception. That started a heated discussion between two office personel and a DPS officer who happened to be in the office. They pulled out more books, made other phone calls, etc. but were unable to reach an agreement. One said Class B license, the other two said Class C.
We took the test, got a Class B license, and travel with slightly more piece of mind.